SS-31 + MOTS-c — Research Evidence Review: Mitochondrial Cardiovascular Mechanisms
Combination evidence review of SS-31 (elamipretide) and MOTS-c in cardiovascular research contexts. Mitochondrial inner-membrane stabilisation + AMPK / metabolic flexibility.
This is a research evidence review of the SS-31 + MOTS-c combination for mitochondrial and cardiovascular research contexts. It is not a protocol. Doses cited below are reported in study context only.
What the combination addresses
The combination targets two distinct axes of mitochondrial homeostasis:
- SS-31 (elamipretide) — a four-amino-acid peptide that selectively binds cardiolipin on the inner mitochondrial membrane. Cardiolipin is essential for the function of the electron transport chain (particularly Complex IV) and for the structural integrity of cristae. In ischaemic, aged, or genetically-compromised mitochondria, cardiolipin oxidation drives loss of bioenergetic function; SS-31 stabilises cardiolipin and preserves cristae structure in published animal-model and in-vitro work.
- MOTS-c — a 16-amino-acid mitochondrially-derived peptide encoded within the 12S rRNA region of mitochondrial DNA. In rodent and cell-culture studies it activates AMPK, promotes metabolic flexibility (improved insulin sensitivity, fatty-acid oxidation), and modulates the mitochondrial unfolded-protein response.
See AMPK & mitochondrial mechanism map for the underlying pathway.
What has been directly studied?
No direct combination study has been published for SS-31 plus MOTS-c. The combination is inferred from monotherapy literature on each compound. See: direct combination evidence vs inferred stacks.
Monotherapy evidence
SS-31 (elamipretide)
The most clinically-developed mitochondrial peptide. Investigated in:
- Primary mitochondrial myopathy (MMPOWER series) — mixed Phase II/III results on functional endpoints (6-minute walk distance, fatigue); biomarker improvements more consistent.
- Barth syndrome (TAZPOWER trial) — cardiolipin abnormality-driven paediatric mitochondrial disorder.
- Heart failure with reduced and preserved ejection fraction (Daubert 2017 and follow-on Phase II) — early signals; not yet definitive.
- Ischaemia/reperfusion in renal and cardiac models — substantial preclinical evidence underpins the clinical programme.
MOTS-c
Predominantly preclinical. The headline finding (Lee 2015, Cell Metabolism) was that MOTS-c reduced high-fat-diet obesity and improved insulin sensitivity in mice via AMPK activation. Several follow-on papers in skeletal muscle, exercise mimetic contexts, and longevity models. Human data is limited to small-scale PK and exercise-response studies.
Why this combination is graded conservatively
- No direct combination study has examined the pair together.
- MOTS-c human evidence is sparse — translation from mouse to human is unproven.
- SS-31 functional endpoints have been inconsistent in clinical trials despite favourable mechanism and biomarker results.
We grade this combination at Grade C in our A–X methodology: preclinical-dominant with limited human translation.
Cardiovascular relevance
The cardiovascular framing for this combination rests on:
- SS-31's direct cardiac trial programme (heart failure, ischaemia/ reperfusion).
- MOTS-c's rodent metabolic-flexibility and cardiac-mitochondria literature.
- The recognised role of mitochondrial dysfunction in heart failure, ischaemic cardiomyopathy, and ageing-related cardiac decline.
The mechanism is plausible. Translation to clinical cardiac outcomes in humans is not established.
Safety signals
- SS-31 has a defined acute and chronic safety profile from the clinical programme — predominantly injection-site reactions, transient headache, mild GI symptoms.
- MOTS-c human safety profile is poorly characterised; no signal in the small studies done.
- The combination has no published safety data — additive or interactive safety cannot be inferred from monotherapy data.
Regulatory status
- UK: both unapproved; no MHRA marketing authorisation. Research material is permissible for laboratory work only. See: UK regulation hub, what 'research use only' means.
- Elsewhere: SS-31 (elamipretide) is investigational; MOTS-c is investigational with no marketed product.
Related on this site
- SS-31 evidence summary
- MOTS-c evidence summary
- Humanin evidence summary
- SS-31 + Humanin — combination evidence review
- AMPK & mitochondrial mechanism map
- Direct vs inferred stacks
Doses reported in published studies
The values below describe doses reported in research-context literature — typically rodent or in-vitro studies, occasionally early human trials. They are not recommendations, not a personal cycle, and not instructions for use. See our responsible information policy.
| Peptide | Dose | Frequency | Timing | Cycle length |
|---|---|---|---|---|
| SS-31 (Elamipretide) | 5–10 mg | Daily SC | Morning | 4–6 weeks (study context) |
| MOTS-c | 5–10 mg | Every other day SC | Morning | 4–6 weeks (study context) |
Reported study-dose timeline
Week-by-week structure as it has been described in published research. Routes appear as recorded by study investigators — this is descriptive, not instructional.
| Peptide | Wk 1 | Wk 2 | Wk 3 | Wk 4 | Wk 5 | Wk 6 |
|---|---|---|---|---|---|---|
| SS-31 | 5 mg/d | 5 mg/d | 10 mg/d | 10 mg/d | 10 mg/d | 5 mg/d |
| MOTS-c | 5 mg EOD | 5 mg EOD | 10 mg EOD | 10 mg EOD | 10 mg EOD | 5 mg EOD |
Routes recorded in studies: SC = subcutaneous · IM = intramuscular · IN = intranasal · Oral · Topical.
Safety signals & UK regulatory context
Frequently asked questions
References
Peer-reviewed sources for the claims above. Where an editor has verified study type, sample size, outcome and limitation, the citation is rendered as a card; otherwise as a plain reference. Links open PubMed or the journal DOI.
First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics
Szeto HH · British Journal of Pharmacology · 2014, 171(8), 2029-50
- Compound(s)
- SS-31
- Main finding
- Review of the cardiolipin-binding mechanism of SS-31 and the rationale for mitochondrial-bioenergetic restoration in ischaemic and degenerative contexts.
- Key limitation
- Review article (single-author, mechanism-centred); does not by itself establish clinical efficacy.
Reported in study context only — not a recommendation or protocol.
Novel mitochondria-targeting peptide in heart failure treatment: a randomized, placebo-controlled trial of elamipretide
Daubert MA, Yow E, Dunn G, et al. · JACC Heart Failure · 2017, 5(9), 635-643
- Model
- Humans — adults with heart failure with reduced ejection fraction (HFrEF)
- Sample size
- n = 36 (Phase I/II dose-escalation)
- Compound(s)
- SS-31 (elamipretide)
- Route in study
- Single intravenous infusion at escalating doses
- Outcome measured
- Safety, tolerability, and exploratory cardiac functional endpoints (LV end-systolic and end-diastolic volumes)
- Main finding
- Single-dose IV elamipretide was well-tolerated with no dose-limiting toxicity through 0.25 mg/kg. Exploratory cardiac volume measurements showed acute reductions at higher doses, hypothesis-generating for the subsequent Phase II programme.
- Key limitation
- Single-dose acute design; small sample; exploratory endpoints. Does not establish chronic-dosing efficacy in HFrEF.
Reported in study context only — not a recommendation or protocol.
The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance
Lee C, Zeng J, Drew BG, et al. · Cell Metabolism · 2015, 21(3), 443-54
- Model
- Mouse — high-fat-diet-induced obesity model and aged mice
- Compound(s)
- MOTS-c
- Route in study
- Intraperitoneal injection, daily
- Outcome measured
- Body weight, insulin sensitivity, AMPK pathway activation, hepatic glucose production
- Main finding
- MOTS-c reduced HFD-induced obesity, improved insulin sensitivity, and activated AMPK in skeletal muscle. Mouse model only.
- Key limitation
- Mouse model; high-dose IP administration not translatable to clinical scenarios. Cohen-lab originated and not extensively replicated in independent laboratories.
Reported in study context only — not a recommendation or protocol.
- Karaa A, Haas R, Goldstein A, Vockley J, Weaver WD, Cohen BH. Randomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy. Neurology. 2018;90(14) :e1212-e1221 doi:10.1212/WNL.0000000000005255 · PMID: 29540588
- Reglodi D, Atlasz T, Szabo E, et al.. PACAP deficiency as a model of aging. GeroScience. 2018;40(5-6) :437-452 doi:10.1007/s11357-018-0045-8 · PMID: 30421409
- Hashimoto Y, Niikura T, Tajima H, et al.. A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta. Proceedings of the National Academy of Sciences USA. 2001;98(11) :6336-41 doi:10.1073/pnas.101133498 · PMID: 11371638
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